General radio wave mass media systems, which use ground broadcast receivers like television sets and radios or PCM broadcast receivers via communications satellites, basically execute unidirectional communication of information to viewers and listeners (hereinafter called "audience side") from broadcasting stations or program sponsors (hereinafter called "broadcasting station side"). Accordingly, orders on TV shopping, responses to quiz programs and questionnaires, applications for goods, privileges and services presented by sponsors, and so forth should be made through post cards purchased by audiences, or via telephones or facsimiles. For example, bidirectional multimedia communication using optical fibers will soon overcome this problem originated from the unidirectional communication, however, various problems are being left before the unidirectional communication is practically used, such as a vast amount of investment needed for improvement on the infrastructure and terminals and practice required to operate the terminals. (In the following description, information from the broadcasting station side to the audience side is called "downward information" and information from the audience side to the broadcasting station side is called "upward information".)
Recently, broadcasting which transmits digital data signals via multiplex broadcast waves for TVs and radios or PCM broadcast waves has been put to practice, and pseudo bidirectional systems have been proposed which accomplish pseudo bidirectionality by transmitting downward information via data signal broadcasting and upward information via a telephone line (for example, "Telecommunicative voting apparatus" in Japanese Patent Application under Laid-open No. Hei 2-110660, "TV-sound oriented data communication system" in Japanese Patent Application under Laid-open No. Hei 3-162030 and "System for measuring audience rating of programs" in Japanese Patent Application under Laid-open No. Hei 1-115232). Since those apparatus and systems are not designed to collect upward information on the aforementioned broadcast programs, however, they can not be used for the purpose as they are unless modified. First, there are a vast number of audiences who may make replies, so that the costs for the terminals and IC cards that are intervened in the system are not appropriate. Secondly, operations to reply to multifarious addresses through general broadcast programs are unnecessarily troublesome.
The present invention has been accomplished in view of the above problems, and it is therefore an objective of the present invention to provide a multibroadcast receiver which is capable of effectively using added information in data signals in broadcast waves to build a pseudo bidirectional radio wave mass media system for a very large audience.